On Thu, 2008-02-21 at 10:53 +0100, Ingo Molnar wrote:
> * Huang, Ying <[EMAIL PROTECTED]> wrote:
>
> > > > -int __initdata early_ioremap_debug;
> > > > +int __initbss early_ioremap_debug;
> > >
> > > will we get some sort of build error if we accidentally do:
> > >
> > > int __initbss early_ioremap_debug = 1;
> > >
> > > ?
> >
> > I tested it just now, and there is no build error.
>
> well, that's bad. We'd silently ignore the " = 1" and boot up with that
> value at 0, right? At minimum we need some really prominent build-time
> _errors_ (i.e. aborted builds) if this ever happens. But ideally,
> shouldnt this whole thing be done at link time? Couldnt the linker sort
> the variables that are zero initialized into the right section, and move
> this constant maintenance pressure off the programmer's shoulder?
I think another method is to add a new attribute into GCC to prepend or
append something to section name instead of just to replace it, like the
example as follow:
#define __initdata __attribute__((section_append(".init")))
int __initdata early_ioremap_debug_data = 1;
int __initdata early_ioremap_debug_bss;
The GCC can deduce the section (.data or .bss) of global variable based
on whether it is initialized. That is, without attribute,
early_ioremap_debug_data will be in ".data", early_ioremap_debug_bss
will be in ".bss". And with section_append attribute,
early_ioremap_debug_data will be in ".data.init" and
early_ioremap_debug_bss will be in ".bss.init".
Best Regards,
Huang Ying
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